CN110139725B - Method and device for producing hard metal compacts, and hard metal compact - Google Patents

Abstract

The present disclosure relates to a method of making a near-net-shape hard metal compact, comprising: providing a multipart mould (82) comprising a plurality of lateral mould parts (90, 92, 94, 96); feeding lateral mold parts (90, 92, 94, 96); -feeding at least two lateral punch parts (100, 102, 104, 106), wherein at least two of the lateral die parts (90, 92, 94, 96) are provided with guide grooves (110, 112, 114, 116) for the lateral punch parts (100, 102, 104, 106); feeding a filling unit (152) through an opening of the cavity (86) and filling the cavity (86) with hard metal powder; feeding at least one upper mold portion (122) defining a portion of an upper side (192) of the cavity (86); -retaining the lateral mould parts (90, 92, 94, 96) and the upper mould part (122); compacting the powder with at least two lateral punch members (100, 102, 104, 106); and opening the lateral die parts (90, 92, 94, 96), the upper die portion (122) and the punch part (100, 102, 104, 106) to remove the compact (10) from the die. The disclosure also relates to a corresponding apparatus (80) and a hard metal compact (10).

Description

Method and device for producing hard metal compacts, and hard metal compact

Technical Field

The present application relates to a method and apparatus for manufacturing a hard metal compact and a hard metal compact. The application also relates to the manufacture of a blank for sintering a component made of hard metal, in particular a cutting tool. The cutting tool may comprise, for example, a cutting insert, an indexable insert, or the like

Background

Hard metal cutting tools are typically sintered at high temperatures. Two main methods are known for producing dimensionally accurate intermediate bodies, also called compacts, blanks or green bodies. One method involves self-forming manufacturing by injection molding. Another method involves making a compact by pressing. The present application mainly relates to the manufacture of compacts for the manufacture of cutting tools and the like by powder metallurgy by compacting hard metal powder under high pressure.

WO2013/024473a1 discloses a tool for manufacturing hard metal compacts, wherein the tool comprises: a central axis defining an axial direction and a radial direction; a base having a through-hole; a radially aligned punch channel and a radially aligned die channel; an upper punch and an opposing lower punch; a plurality of lateral punches arranged in pairs and radially movable in the punch channels; and a plurality of die bars radially movable in the die channel, each die bar associated with two adjacent lateral punches, wherein each die bar has a front die forming surface defined by a die bar peripheral edge and has two die guide surfaces spaced rearwardly therefrom, and wherein the two adjacent lateral punches are slidably movable on the die guide surfaces of a common die bar.

The tool can be used substantially to form more complex profiles suitable for cutting tools. However, such tools are complex in construction and must be operated with a high level of control. In particular, the parallel control of the main punches (upper and lower punches) and the sub-punches (side punches) is time consuming.

A disadvantage of this tool concept is that the following is not possible with the described tool construction: a cutting plate without a cutting edge is manufactured, for example, by pressing in the context of the present application, and is not affected by parting planes or burrs, in particular intersections. The same applies to compacts of similar design.

Similar tool concepts are known from DE102013204370a1, DE102010048183a1 and WO 2015/120496a 1. In such tools, the main punch shaft is always formed by an upper punch and a lower punch. Even if any lateral punch is provided, it will not form the main punch, but only the auxiliary punch. The hard metal compact manufactured in this way has a certain microstructure determined by the main pressing direction.

One example of a cutting insert is a so-called indexable insert. Such an indexable insert is described in DE102012108752B of the applicant. An advantage of such an indexable insert is that it has 4 cutting edges, wherein the cutting insert consists of two substantially identical parts, offset from each other by 180 °, each part forming two cutting edges. In other words, the cutting insert may be rotated 180 ° about the centre axis, so that two cutting edges may be obtained. In addition, the cutting insert may be rotated a total of 180 ° about an axis perpendicular to the central axis, whereby (after a corresponding orientation with respect to the rotational orientation of the central axis) two further cutting edges may be used.

Blanks for these parts are usually manufactured by injection moulding and require substantial reworking.

Cutting inserts of the above-mentioned type, in particular cutting inserts known as tangential cutting inserts, are commonly used in metal machining applications, in particular in milling or turning applications. Conventionally, existing cutting inserts are used for so-called face milling or shoulder milling. Milling tools using such cutting inserts typically comprise a rotationally symmetric tool holder to the periphery of which at least one, but usually more, of the above-described sets of cutting inserts are releasably secured.

The removal of material from the workpiece during milling is ensured by the high-precision cutting inserts or edges formed in the cutting insert. In order to minimize wear, and to withstand the very high cutting forces generated during machining and to ensure maximum accuracy, these cutting inserts are usually made of hard metal. However, due to the high material stresses, the cutting edge is subject to wear over time. Thus, in particular in milling operations requiring high precision, the cutting inserts must be replaced after a certain time.

In order to prevent relatively expensive cutting inserts from having to be completely replaced each time the inserts wear, multi-sided cutting inserts have been developed, which have a plurality of inserts arranged symmetrically to each other.

In addition, it is noted in the design of dies used for powder metallurgy manufacturing of hard metal compacts that no moulding pitch is provided extending through or across the cutting edge. However, the cutting edge is preferably at the parting plane. This may result in blanks for certain cutting tools that cannot be manufactured by pressing without post-processing or restrictive post-processing.

Another challenge in the design of press tools for making compacts for hard metal tools is the demolding of inclined, sharp-chamfered or tangentially-transitioning die faces into parting planes. This often results in that the part of the mould or the part of the press that is designed into the shape of the compact must be made very thin-walled or pointed, at least in part. Thereby increasing the risk of wear and tear and it is therefore preferable to avoid this risk.

The compaction of hard metal compacts is carried out at very high pressures, which may range from about 2000 to about 4000bar (0.2 to 0.4 GPa). The pressing of hard metal powders is not comparable or even equivalent to the pressing of metal powders or other powder materials. One reason for this is the so-called spring behaviour of the compacted hard metal compact. In contrast to compacts based on metal powder compaction, plasticizers (e.g. paraffin, wax) are a non-negligible part of their composition and are porous, i.e. they have air pockets or cavities. The elastic behavior can be reflected in, for example, an increase in volume after compression, which can be up to about 3% of the initial volume.

Pressing devices for hard metal pressing usually rely only on a main punch, which is arranged on a main pressing shaft, without further punches being provided. As mentioned above, the main punches are typically an upper punch and a lower punch which are vertically movable, in particular movable towards each other to create a compact.

In the field of hard metal powder metallurgy, these main punches cannot be supplemented simply by other (lateral) punches which are designed as substantially similar slides during injection molding, but which act as punches. On the one hand, this is due to the high pressure during pressing. Moreover, such (lateral) punches can have a negative effect on the compaction density distribution of the compact. In the context of the present disclosure, a pressed density distribution is also referred to as a pressed structure distribution.

The above limitation does not exclude the use of sometimes a secondary or auxiliary punch, which moves along a plane inclined with respect to the vertical direction. However, such auxiliary punches are typically used only to generate secondary profiles, such as holes, side slots, and the like. The effective area of such an auxiliary punch acting on the compact is usually much smaller than the area of the corresponding side of the die wall surrounding the compact.

In order to produce as favorable a component structure as possible, in particular with a sufficiently uniform compaction density, it is generally desirable to dimension the main punch in such a way that, viewed in the vertical direction, it covers the contour or periphery of the compact as completely as possible. If this is not the case, the main punch will be significantly smaller than the profile of the compact, which will result in an unfavorable stress or pressure gradient during pressing, since the entire cross section of the compact cannot be directly exposed to the pressure generated (mainly) by the main punch.

In addition to the punch, the die used for pressing the blank is usually used for producing other die components of hard metal cutting tools, which do not actively participate (as a driving punch) during the pressing process. Such mould parts can in principle be movable and are therefore referred to as slides. However, solid mold parts are also conceivable. Typically, the mold parts themselves do not move during the pressing process. Moving mold parts, such as slides or the like, move to perform the ejection process to form the green compact.

Disclosure of Invention

On this background, it is an object of the present application to provide a method and an apparatus for the near-net-shape production of hard metal compacts, in particular for the production of sintered blanks for cutting tools, which allow a high degree of freedom in the design of the tool geometry and the production of compacts having an advantageous compaction structure or an advantageous compaction density. In particular, the manufacture of hard metal compacts having a plurality of symmetrical designs will be simplified. This may involve a compact whose cutting edge is rotationally symmetrical with respect to an axis, for example the central axis, which is designed to be rotationally symmetrical with respect to a median plane. In this way, the resulting cutting tool can be rotated about two spatial axes, so that one of the 4 cutting edges can be brought into position in each case.

This also applies in particular to compacts of cutting tools having cutting edges which are oriented in opposite directions and which face away from one another. In addition, the manufacture of hard metal compacts for cutting tools should be described as far as possible, which allows production to be unaffected by shape divisions or burrs, in particular intersecting cutting edges. Finally, a method and a device are specified which allow the use of particularly robust design punches and preferably also die parts which in particular do not comprise excessively thin pointed portions.

The object of the present application is achieved by a method for near-net shape manufacturing of a hard metal compact, in particular for manufacturing a sintered blank for a cutting tool, comprising the steps of:

-providing a multi-part die comprising a plurality of lateral die parts defining sides of a cavity for the compact,

wherein at least one of the lateral mould parts further defines a part of the upper side of the cavity,

-feeding the lateral mould parts,

-feeding at least two lateral punch members,

wherein at least two of said lateral die parts are provided with guide grooves for lateral punch parts,

-feeding a filling unit through an opening of the cavity and filling the cavity with hard metal powder,

-feeding at least one upper mould part defining a part of the upper side of the cavity,

-holding the lateral mould parts and the upper mould part,

-compacting the powder with at least two lateral punch members, and

-opening the lateral die part, the upper die part and the punch part to demould the compact.

In this way the object of the invention is fully achieved.

This method allows the manufacture of compacts which previously could only be produced with high post-processing requirements. In addition, the method may at least partially replace or at least supplement the manufacture of sintered blanks for cutting tools by injection molding. The arrangement of the lateral die part and the lateral punch part allows a higher degree of freedom in design. In particular, workpieces can be pressed and demolded, which workpieces cannot be easily produced by pressing according to conventional methods.

The method according to the application has the advantage that the die part and punch part used can be made very strong without excessive wall thickness reduction. In addition, the method allows for advantageous microstructural or pressing paths in the arrangement of the die part and the punch part during pressing. The green compacts produced in this way have a high homogeneity.

In the manufacturing process, a compact for a part can be manufactured, and excellent production and grinding performance is provided on the manufactured cutting edge. In pressing, the cutting edge can be produced close to or even in the final contour without extensive post-treatment by grinding.

Preferably, the upper mould part releases the opening of the cavity when the upper mould part is removed from the cavity, thereby serving to fill the cavity with hard metal powder.

In an exemplary embodiment, the at least one lateral mold part forms part of an upper side of the cavity. The upper mould part forms a further (different) part of the upper side of the cavity. In another exemplary embodiment, the same mold part or another mold part forms part of the underside of the cavity. This forms a further (different) part of the underside of the cavity when the lower mould part is used.

Preferably, the method is suitable for producing a compact, on the basis of which a cutting tool or cutting insert is produced, said cutting tool having an essentially symmetrical (but twisted to each other) upper side and a lower side, between which upper and lower side a peripheral area is formed which extends in the clamping surface or cutting groove of the cutting. The open space of the cutting edge is preferably associated with the upper side or the lower side. The cutting edge is partially associated with a portion of the upper side or the lower side.

The holding of the mould parts may be performed by force control and/or path control. The purpose of the retention is to ensure such a position. Thus, the retention may be accomplished, for example, by form fit, adhesion, or combination. The retention may also be referred to as locking or fixing, even if the position assurance is essentially achieved by applying a correspondingly high retention force.

Preferably, no further punch parts are provided in addition to the transverse punch part, in particular the vertical punch part. The main punch is a lateral punch member. According to an exemplary embodiment, only transverse punch members are used. In other words, the manufacturing process differs from a conventional pressing operation in which the compact of a hard metal tool is mainly compacted by a vertical punch defining the main pressure axis.

According to an exemplary embodiment, the method further comprises the steps of:

-providing at least one of said lateral mould parts, further defining a portion of the underside of said cavity,

-providing at least one lower mould part defining a part of the underside of the cavity, and

-holding the lower mould part together with the lateral mould parts and the upper mould part.

In this way, there is no punch on the upper side of the cavity and on the lower side of the cavity, wherein the cavity is filled with hard metal powder through the upper side of the cavity. The desired shape of the compact on the upper and lower sides may be defined by the lower and upper die parts. In addition, in particular, the transition between the upper/lower base surface and the peripheral area of the compact, such as radius, chamfer, etc., can be defined by the (lateral) die part. One advantage of this design is that the lateral mould parts can be made thick-walled in this region. This increases the robustness and the service life of the mould.

According to a further exemplary embodiment, at least one lateral mould part is provided, which, in addition to at least one side of the cavity, also forms part of the lower side and part of the upper side of the cavity.

According to another exemplary embodiment, the lateral die parts, the upper die part and the lower die part are locked or held during compaction, wherein the lateral punch parts move to compact the powder. Preferably, there are no further punch members other than the lateral punch members. However, according to at least some embodiments, the provision of auxiliary punches or the like is not completely excluded. Preferably, however, the lateral punch members define a main punch axis or main punch axis.

The lateral mould parts, the upper mould part and the lower mould part are preferably fixed during the pressing or pressing. Compaction is accomplished by the punch member.

According to a further exemplary embodiment, the pressing comprises a lateral pressing by the punch part, wherein the respective direction of movement of the punch part is oriented parallel to a plane which is inclined, in particular perpendicular, to the feed direction of the upper mould part.

Thus, for example, the main pressing direction is oriented parallel to the horizontal plane, not perpendicular to the horizontal plane. Preferably, a plurality of punch members are provided, arranged generally in a star shape around the cavity. In this way, a plurality of press shafts can be realized, so that a uniform structure as a whole can be realized.

According to a further exemplary embodiment, the lateral die parts and the punch part are movable parallel to a first plane, in particular a horizontal plane, wherein the upper die section, in particular the lower die section, is movable parallel to a second plane, in particular a vertical plane. In other words, the mold part is preferably movable perpendicular to the direction of movement of the upper or lower mold part. Each punch member is movable in a transverse direction relative to the cavity.

According to another exemplary embodiment, the upper die part is coupled to a vertical slide, which forms a recess in the compact, in particular a recess passing vertically through the compact, wherein the vertical slide is movable parallel to the upper die part, and in particular the lower die part is also coupled to the respective vertical slide.

Alternative embodiments are conceivable in which the vertical slides are integrated into the upper and/or lower mould part. According to a further exemplary embodiment, the upper mould part and the associated slide and the lower mould part and the associated slide are movable relative to each other.

Preferably, the upper mold portion has a guide groove for vertical sliding. Preferably, the lower mold portion has a guide groove for vertical sliding. Thus, a compact design of the mold can be achieved. If two vertical slides, one upper vertical slide and one lower vertical slide, can be used, a recess or through hole can be formed in the compact that is completely or substantially symmetrical with respect to the horizontal center plane of the compact.

According to another exemplary embodiment, the step of feeding the lateral mould parts comprises feeding three or more lateral mould parts, which lateral mould parts are movable towards and away from each other to open or close the cavity.

According to at least some example embodiments, the cavity is formed by only the movable die piece and the punch. Thus, the cavity is not formed by a solid mold part. The three or more lateral mould parts are substantially circular and/or circumferentially distributed around the centre of the cavity and may be moved towards the centre of the cavity.

According to an exemplary refinement of this embodiment, the lateral die parts together define the horizontal boundary of the compact. In other words, the peripheral portion of the compact extending between the upper and lower base surfaces is not formed by the solid/rigid mold member. The freedom of design is further increased if the cavity on the mould side is formed completely or almost completely by the movable mould part.

According to another exemplary embodiment, the cavity and the resulting shape of the compact are completely defined by the movable die part and the punch part.

According to another exemplary embodiment, each lateral die part is associated with a punch part arranged in a guide groove, wherein the direction of movement of the punch part is parallel to the direction of movement of the lateral die parts. In this way, a compact can be manufactured on the basis of which a cutting insert having a plurality of cutting edges can be manufactured.

According to a further exemplary embodiment, at least two punch parts, in particular two pairs of punch parts, are vertically offset from each other. This has the advantage that a particularly homogeneous and advantageous microstructure can be achieved. Thus, the compact is compacted not only in one direction, but also in two or even more directions. This design also has the advantage of allowing greater design freedom for the die parts of the die, since more areas of the resulting cavity can be pressurized by the punch member.

According to another exemplary embodiment, the punch member forms part of the shape of a compact, which cannot be demoulded vertically. In particular, these can be clamping surfaces of trough-like configuration. In particular, when the compact has three, four or more edges, which are distributed over a substantially peripheral area of the compact, the clamping surface cannot be easily removed from the die according to the conventional method.

According to another exemplary embodiment, the lateral die part forms a transition between the peripheral area and at least one of the upper or lower base surface of the compact, which transition in particular comprises a radius or a chamfer.

Such areas are not easily formed by the upper and/or lower mold portions. This results in a significant reduction in the wall thickness of the vertically movable mould part. It is advantageous that the lateral die parts can be moved, since in this way corresponding transitions can be formed on the upper and lower side of the compact. However, when the die member is movable, the green compact can be easily removed from the die.

According to another exemplary embodiment, at least one of the upper or lower base surfaces of the compact in the cavity, preferably both base surfaces, is manufactured without a punch. In other words, the punch-less manufacture of the upper and/or lower base surface allows a micro-structured course determined mainly by the lateral punches.

According to another exemplary embodiment, for forming a compact for a rhomboidal-shaped indexable insert, 4 lateral die parts are provided, which at least partially define 4 side faces of the compact and are coupled to 4 lateral punch parts, 4 clamping surfaces being defined on 4 peripheral sides of the compact, an upper die part for forming an upper base face, a lower die part for forming a lower base face, an upper die part coupled to an upper vertical slide, a lower die part coupled to a lower vertical slide, the upper and lower vertical slides together forming a passage opening in the compact.

Such a compact is particularly suitable for the manufacture of indexable inserts which are provided with, for example, 4 cutting edges, which are divided into two pairs. In each case, a pair of cutting edges is allocated to the upper side of the compact and to the lower side of the compact. The upper pair of cutting edges are arranged opposite to each other. The lower pair of cutting edges are disposed opposite to each other. The pairs of upper and lower cutting edges are laterally oriented with respect to each other. Such an indexable insert is described by way of example in DE102012108752B 3.

The diamond shape may also be described as a diamond. Specifically, the clamping surface is a clamping recess on one side of the peripheral area of the compact.

The present application also provides a method of manufacturing a hard metal cutting tool, in particular a cutting insert, comprising:

-manufacturing a compact according to the present application,

-processing the part with or without limited post-processing, in particular transferring from a pressing apparatus to a sintering apparatus, and

-sintering the compact.

Processing the component is to be understood in particular as component processing, which includes, for example, transferring the compact from a compaction apparatus to a sintering apparatus. Optionally, temporary storage may be performed therebetween. At the same time, defined machining steps, such as automatic deburring, can be carried out on the green compact. Deburring can be accomplished by brushing or blow molding, and typically involves green components of the compact.

The preparation of the compact according to one embodiment of the method described herein significantly reduces the post-processing requirements.

The object of the present application is achieved by an apparatus for near-net shape manufacturing of a hard metal compact, in particular for manufacturing a sintered blank for a cutting tool, comprising: a bed; a multi-part die configured to form a cavity for a compact, the die comprising a plurality of lateral die parts defining sides of the cavity, wherein at least one of the lateral die parts further defines a portion of an upper side of the cavity; an upper mold portion defining a portion of an upper side of the cavity; a punch unit having at least two lateral punch parts, wherein at least two of the lateral die parts are provided with guide grooves for the lateral punch parts; a filling unit having a filling shoe which can be fed to an opening of the cavity in order to fill the cavity with hard metal powder, wherein the lateral die part and the upper die part are movable between an open position and a closed position, wherein the lateral die part and the upper die part define a surface of the compact in the closed position, wherein the lateral punch part is movable along a guide groove in the lateral die part to compact the powder, wherein the direction of movement of the lateral punch part is oriented parallel to the following planes: the plane is inclined with respect to the feeding direction of the upper mould part, in particular perpendicular to the feeding direction of the upper mould part.

According to an exemplary embodiment, the device has a lower mould part defining a part of the underside of the cavity, wherein at least one lateral mould part also defines a part of the underside of the cavity, and the lateral mould parts, the upper mould part and the lower mould part can be locked in a closed position.

According to a further exemplary embodiment, the lateral die part and the lateral punch part are movable parallel to a first plane, in particular a horizontal plane, wherein the upper die portion, in particular the lower die part, is movable parallel to a second plane, in particular a vertical plane.

According to another exemplary embodiment, the device further comprises a holding unit or fixing unit which fixes the lateral die parts, the upper die part and the lower die part in the closed position to form the peripheral portion of the compact.

According to another exemplary embodiment, the upper die part is coupled to a vertical slide forming a recess in the compact, in particular a recess extending vertically through the compact, wherein the vertical slide is movable parallel to the upper die part, in particular the lower die part is also coupled to the respective vertical slide.

According to another exemplary embodiment, the compaction of the powder is performed substantially, preferably exclusively, by the lateral punch members.

According to another exemplary embodiment, the lateral die part forms a transition between a peripheral area of the compact and at least one of an upper or a lower base surface of the compact, in particular the transition comprises a radius or a chamfer.

According to another aspect of the present application, there is provided a hard metal compact, in particular a compact for a rotary tool, manufactured with or without limited post-processing, the compact having: two base surfaces arranged opposite each other, a peripheral area extending between the two base surfaces and a plurality of cutting edges, which are defined by a parting plane of the die, wherein at least one cutting edge is associated with a first base surface and at least one cutting edge is associated with a second base surface, wherein the cutting edges are associated in the peripheral area with a trough-shaped clamping surface, which is not perpendicular to the base surfaces and is demouldable, wherein the cutting edges and the clamping surface are at least partially defined by a punch member which can be fed transversely to the normal of the base surfaces and which achieves a correspondingly oriented micro-structure, the base surfaces being free of punches, being defined by lateral die members which can be fed transversely to the normal of the base surfaces and lateral die members which can be fed parallel to the normal of the base surfaces.

The object of the present application is also fully solved in this way. Such a compact may be manufactured according to embodiments of the method described herein. Preferably, a compact is manufactured in one embodiment of the apparatus described herein.

Specifically, the compact is a hard metal cutting insert having 4 cutting edges (A, B, C, D), wherein two (A, B and C, D) of the 4 cutting edges (A, B, C, D) are each rotationally symmetric about a central axis. In addition, there is symmetry between the upper surface (including inserts a and B) and the lower surface (including inserts C and D) of the cutting insert. Preferably, the compact does not have any intersecting burr with the cutting blade of the cutting edge caused by the die of the pressing device.

If the cutting tool is manufactured on the basis of a compact manufactured with or without limited post-processing, it is contemplated that the cutting tool may be manufactured according to an embodiment of the method described herein and/or an embodiment of the device described herein. In particular, burrs, the course of the separation plane and other designs, including areas that cannot be easily removed, for example by (lateral) sliding, allow corresponding conclusions to be drawn.

In particular, the green compact can be manufactured with limited or no post-processing: cutting edges, tangential transitions, clamping recesses, open spaces or clearance angles, tapers, etc.

The present application is not limited to such cutting inserts, in particular to the above-described inserts having 4 specific arrangements and alignments. However, for the purposes of illustration, reference is made to this type of cutting insert.

It is to be understood that the features of the disclosure which are explained below and are explained below can be used not only in the respectively specified combination but also in other combinations or alone without the scope of the invention.

Drawings

Other features and advantages will become apparent from the following description of the preferred embodiments, which refers to the accompanying drawings. In the drawings:

FIG. 1 illustrates a perspective view of a hard metal cutting tool that may be fabricated in accordance with at least some aspects of the present invention;

FIG. 2 shows a top view of the apparatus of FIG. 1;

fig. 3 shows a first side view of the device according to fig. 2;

fig. 4 shows a second side view of the device according to fig. 2;

FIG. 5 shows a partial perspective view of a tool head that may be provided with a hard metal indexable insert;

fig. 6 shows a schematic perspective view of a pressing device of a hard metal compact in a disassembled state;

fig. 7 shows a perspective view of the device according to fig. 6 in a closed state;

FIG. 8 shows a top view of the device of FIG. 7;

fig. 9 shows a cross-sectional view of the device according to fig. 8 along the line IX-IX;

figure 10 shows a cross-section of the device according to figure 8 along the line X-X;

fig. 11 shows a further perspective view of the device according to fig. 6 in the orientation according to fig. 7, wherein the device is in a second state;

FIG. 12 shows a top view of the device of FIG. 11;

FIG. 13 shows a cross-sectional view of the device of FIG. 12 along line XIII-XIII;

FIG. 14 shows a cross-sectional view of the device of FIG. 12 along the line XIV-XIV;

fig. 15 shows a further perspective view of the device according to fig. 6 in the orientation according to fig. 7, wherein the device is in a third state;

FIG. 16 shows a top view of the device of FIG. 15;

figure 17 shows a cross-sectional view of the device according to figure 16 along the line XVII-XVII;

figure 18 shows a cross-section of the device according to figure 16 along the line XVIII-XVIII; and

fig. 19 shows a schematic block diagram for explaining an exemplary embodiment of a method of manufacturing a hard metal compact.

Detailed Description

Referring to fig. 1, 2, 3 and 4, there is shown an exemplary embodiment of a compact 10 that may be used in powder metallurgy to manufacture hard metal tools, particularly cutting inserts. Preferably, in accordance with at least some embodiments of the present disclosure, the compact 10 may be manufactured by powder compaction without post-processing or restrictive post-processing. However, this requires a specific design of the apparatus or a specific method for manufacturing the compact 10.

An at least similarly designed cutting insert is known from DE102012108752B 3. However, up to now, sintered blanks for producing such cutting tools have to be produced by injection molding and extensive post-processing. According to the present application, the compact 10 may be produced by a pressing process without post-treatment or limited post-treatment. In other words, the production of sintered blanks based on injection moulding can be replaced by a pressing method which at least approximates net shape.

It should be understood that the compact 10 is intended primarily as an example of a wide variety of other compacts that may be prepared using the apparatus and/or the method according to the aspects and embodiments described herein.

Referring to fig. 1, 2, 3 and 4, it can be seen that the compact 10 has a total of 4 cutting edges 12, the 4 cutting edges 12 being indicated in fig. 1 by 12a, 12b, 12c and 12d (not visible in fig. 1). In addition, the compact 10 has a central axis 14, the central axis 14 being defined by a recess 18. The central axis 14 is also an axis of symmetry for some design features. The recess 18 is used to secure a cutting insert produced based on the compact 10 to a tool.

The first cutting edge 12a and the second cutting edge 12b may be used in succession when the cutting insert based on the compact 10 is rotated 180 ° about the central axis 14. However, the compact 10 has a total of 4 profiles, which define the cutting edges 12a, 12b, 12c, and 12 d.

In order to be able to use the additional cutting edges 12c and 12d, the compact 10 is designed not only with 180 ° rotational symmetry with respect to the central axis 14. In addition, a middle or symmetry plane 20 is also provided, see fig. 3. In other words, the cutting edges 12a, 12b are arranged on one side of the median plane 20 and the cutting edges 12c and 12d are arranged on the opposite side of the median plane 20. Thus, a cutting tool based on the compact 10 may be flipped for use starting from one side of the central plane 20 to the other. In other words, a cutting insert based on compact 10 may be rotated about central axis 14 and/or about another axis located in mid-plane 20 such that one of the 4 cutting edges 12a, 12b, 12c, and 12d may be used.

The intermediate plane 20 divides the compact 10 into a first part 24 and a second part 26, which are designed substantially similar, preferably identical, and have a defined rotational position relative to each other.

Base surfaces 28, 30 are provided on the green compact 10. The base surface 28 may also be referred to as an upper base surface. The base surface 30 may also be referred to as a lower base surface. The base surfaces 28, 30 extend substantially parallel to the middle plane 20.

A peripheral region 32 is provided between the base surfaces 28 and 30. By way of example, the peripheral region 32 comprises a total of 4 (lateral) sides, each of which is provided with one of the cutting edges 12a, 12b, 12c and 12 d.

The cutting edges 12a, 12b, 12c, and 12d each include a cutting edge 34, the cutting edge 34 extending between a clamping surface 36 and a free surface 38. The clamping surface 36 may also be referred to as a clamping groove. The free surface 38 is disposed on one of the base surfaces 28 and 30. In particular, it can be seen from the illustration shown in fig. 4 that the free surface 38 is slightly inclined with respect to the base surfaces 28, 30 and the central plane 20.

In addition, the green compact 10 has 4 contact surfaces 40 in total, each of which is disposed on one side of the peripheral region 32. The contact surface 40 is configured to align the compact 10 when the compact 10 is received on the machining tool 60 (see fig. 5).

On each of the 4 sides of the peripheral region 32, a respective cutting edge 12 is associated with a contact surface 40 of one of the two base surfaces 28 and 30 and the other of the base surfaces 28, 30. The opposite sides of the peripheral region 32 have a 180 deg. rotationally symmetrical design with respect to the central axis 14. Adjacent sides of the peripheral region 32 have an alternating relationship between the cutting edge 12, the contact surface 40 and the base surfaces 28, 30, see fig. 1-4.

As can be seen in fig. 2, the compact 10 has a diamond design, i.e. a slight cross. In fig. 2, the lateral directions indicated by 46, 48 are defined as the normals to the contact surface 40, respectively. It can be seen that the directions 46, 48 are not exactly perpendicular to each other.

Fig. 5 uses a partial illustration of the machining tool 60 to illustrate a possible use of the cutting insert 66, which cutting insert 66 may be manufactured based on the compact 10. The cutting insert 66 may also be referred to as a cutting plate. Specifically, the cutting insert 66 is formed as an indexable insert having 4 cutting edges.

The machining tool 60 shown by way of example is an end mill provided with a shaft 62. At the machining end of the shaft 62, 4 pockets 64 are formed, the pockets 64 having corresponding recesses for receiving cutting inserts 66. The position assignment and alignment of the cutting insert 66 takes place here by means of the contact surface 40 and the base surfaces 28, 30, see fig. 1 to 4. The fixation of the cutting insert 66 is usually achieved by means of a screw or similar fastening element, which protrudes through the recess 18. The cutting insert 66 may also be referred to as a tangential tool.

As shown with reference to fig. 1-5, embodiments of the compact 10 and cutting insert 66 based on the compact 10 show that the preliminary forming of the respective sintered blank is affected by certain boundary conditions.

On the one hand, 4 cutting edges 12a, 12b, 12c, and 12d are formed on the peripheral area 32 of the compact 10. This means that conventional punching tools having an upper punch and a lower punch defining a main pressing axis cannot be used to form the respective profiles on all 4 sides of the peripheral area 32.

However, it is advantageous to arrange the compact 10 such that the base surfaces 28, 30 in the cavity of the press tool are associated with the upper and lower sides, respectively. In other words, a lateral shaped portion must be provided to form the peripheral region 32. With reference to fig. 4, it can be seen that the groove-like design of the clamping surface 36 cannot easily be removed "from above" or "from below", i.e. parallel to the central axis 14. In particular, a transition from the free surface 38 to the clamping surface 36, i.e. a thin conical profile, is produced in the region of the cutting edge 34. The hard metal powder cannot be easily compacted "from above" or "from below" using a punch in this region. A fracture or the like will be broken in the area of the cutting edge 34.

However, if the regions of the free surface 38 and the clamping surface 36 are formed solely by the stationary mold part, a sufficiently high pressing pressure cannot be generated in this sharp edge region. In other words, an area that is not sufficiently compacted may occur in a later high-load area of the compact 10.

Another boundary condition relates to a desired microstructural path or a desired microtexturing in the cutting edges 12a, 12b, 12c and 12 d. During operation, each of the 4 cutting edges 12a, 12b, 12c, 12d should have similar or even identical characteristics, i.e. service life, strength, etc. For this reason, the compact 10 cannot be produced with a press tool having, for example, an upper punch and a lower punch as a main punch, which are engaged with a (lateral) auxiliary punch. This design may result in that the required uniformity is not easily achieved without post-processing, involving the cutting edges 12a, 12b, 12c, 12 d.

One way of manufacturing a sintered blank with a design according to fig. 1, 2, 3 and 4 is therefore injection moulding. However, this still requires a considerable degree of post-processing. In addition, the hard metal powder cannot be distributed uniformly by injection molding as in the pressing method according to the invention, which leads to a significant dimensional difference between the 4 cutting edges in the sintered injection-molded part.

Advantageously, the course of the cutting edge 34 of the respective cutting edge 12 is defined by a parting line or parting plane in the pressing tool. Another boundary condition is that the separation rate is set as little as possible in the transverse direction of the cutting edge 34.

Referring to fig. 6-18, aspects and embodiments of the apparatus and a near-net-shape manufacturing method for a hard metal compact are described below by way of example. The apparatus is generally indicated at 80. According to at least one embodiment, the apparatus 80 is configured to manufacture a hard metal compact based on hard metal powder, the shape of which is at least similar to the shape of the compact 10 shown with reference to fig. 1 and 4.

For purposes of illustration, fig. 6-18 show simplified representations of the components of the compact 10 and apparatus 80. The orientation of the compact 10 and the device 80 is shown by the coordinate system X, Y, Z, such orientation being shown in fig. 7, 11, and 15. In the exemplary embodiment shown, the Z-axis represents the height direction or vertical direction. Each plane parallel to the Z axis may be referred to as a vertical plane. The X-axis represents the longitudinal direction. The Y-axis represents the lateral direction. The X-axis and Y-axis may be collectively referred to as the lateral axis. The X-axis and the Y-axis together define a horizontal plane perpendicular to the Z-axis and perpendicular to the vertical plane.

It should be understood that other arrangements and names may be used. Conceivable variations and arrangements will be readily understood by those skilled in the art. The same applies to position and orientation information such as above, below, lateral, transverse, front, rear, etc. Hereinafter, for purposes of illustration, reference will be made repeatedly to coordinate system X, Y, Z.

The device 80 comprises a mould 82, which is designed as a multipart mould. The mold 82 is coupled to a bed 84 or mounted on the bed 84. The bed 84 may also be referred to as a support or frame. The die 82 forms a cavity 86, and the cavity 86 may be filled with hard metal powder to form the compact 10 by applying pressure.

The mold 82 includes lateral mold members 90, 92, 94, 96. The mold parts 90, 92, 94, 96 are movable parallel to a horizontal plane. In other words, the mold parts 90, 92, 94, 96 may be moved between the open and closed positions. For example, the mold parts 90, 94 may be moved in the X direction. Thus, the mold members 92, 96 may be moved, for example, in the Y direction. The mold parts 90, 92, 94, 96 may be moved toward and away from each other. The die members 90, 92, 94, 96 are arranged in a circle about the central axis 14 of the compact 10 to be manufactured. The central axis 14 is parallel to the Z direction.

The apparatus 80 further comprises a punch unit 98, which for example comprises punches 100, 102, 104, 106. Punches 100, 102, 104, 106, together with die components 90, 92, 94, 96, form at least one circumferential region (reference numeral 32 in fig. 1) of compact 10 in cavity 86.

In particular, punches 100, 102, 104, 106 may be referred to as lateral punches or lateral punch components. In other words, the punches 100, 102, 104, 106 are not designed to move "from above" or "from below" parallel to or along the Z axis as is typical to act on the powder contained in the cavity 86. Instead, the punches 100, 102, 104, 106, such as the die members 90, 92, 94, 96, are designed and adapted to move parallel to the horizontal plane defined by the X and Y axes to set and compact the powder contained in the cavity 86 under pressure.

Preferably, the punches 100, 102, 104, 106 are movable parallel to the die members 90, 92, 94, 96. In this manner, the die components 90, 92, 94, 96 at least partially serve as guides for the punches 100, 102, 104, 106.

A punch 100 is associated with the die member 90. A punch 102 is associated with the die component 92. A punch 104 is associated with the die component 94. A punch 106 is associated with the die member 96.

A guide groove 110 for the punch 100 is formed in the die member 90. A guide groove 112 for the punch 102 is formed in the die member 92. A guide groove 114 for the punch 104 is formed in the die member 94. A guide groove 116 for the punch 106 is formed in the die member 96.

Preferably, at least according to an exemplary embodiment, no further punches, in particular no vertical punches, are provided in addition to the punches 100, 102, 104, 106 designed as lateral punches. In other words, a difference from the known principle has been created, i.e. the punch can now be fed mainly laterally to the cavity 86 in order to form the compact 10.

The cavity also includes a lower mold portion 120 and an upper mold portion 122. To form the recess 18, sliders 124, 126 are also provided. A slide 124 is associated with the lower mold portion 120. A slide 126 is associated with the upper mold portion 122. The slides 124, 126 may also be referred to as vertical slides. When the cavity 86 is closed, the slides 124, 126 contact each other. In this way, the area in the cavity 86 where the recess 18 is subsequently formed in the compact 10 is blocked.

The lower mould part 120 is provided with a guide groove 128 for the slide 124. The upper mould part 122 is provided with a guide groove 130 for the slide 126.

In fig. 8, the directions of movement of the die components 90, 92, 94, 96 and punches 100, 102, 104, 106 are represented by arrows 140, 142, 144, 146. Pairs of die parts and punches 90, 100; 92. 102, and (b); 94. 104 and 96, 106 are each movable parallel to each other but at least partially independently to define the cavity 86 to compact the metal powder contained in the cavity 86 and release the resulting compact 10.

In fig. 8, the holding unit 150 associated with the mold parts 90, 92, 94 and 96 is also shown highly simplified with reference 150. In addition, a holding unit 150 is also associated with the lower mold portion 120, the upper mold portion 122, and the vertical slides 124, 126 (if present). During the pressing operation, the mold parts 90, 92, 94, and 96, the lower mold portion 120, the upper mold portion 122, and the slides 124, 126 are forcibly locked or retained. In other words, these assemblies do not act as punches.

The apparatus 80 has 4 locking or retaining shafts for the mold parts 90, 92, 94 and 96. In addition, a locking shaft or a retaining shaft is provided for the lower mold portion 120 and the upper mold portion 122, respectively. Optionally, separate locking and retaining shafts for the vertical slides 124, 126 are provided. It is also conceivable to control the lower mould part 120 and the associated slide 124 and the upper mould part 122 and the associated slide 126 by means of a locking shaft or a retaining shaft, respectively.

In addition, the punch unit 98 of the device 80 has 4 punch shafts for the punches 100, 102, 104, 106, which 4 punch shafts act laterally on the metal powder contained in the cavity 86.

In fig. 9, the filler cells are indicated in a schematically simplified form by 152. The filling unit 152 comprises a filling shoe 154, which filling shoe 154 can be fed to the opening of the cavity 86 in order to fill the cavity 86 with hard metal powder. An exemplary feed direction for the filling shoe 154 is indicated at 156 in FIG. 9. For example, the slides 126 associated with the upper mold portion 122 and/or with the upper mold portion 122 may first be removed from the cavity 86 to enable the filling shoe 154 to be directed to the filling unit 152. Once the desired amount of hard metal powder has been introduced into the cavity 86, the filling shoe 154 may be removed. The upper mold portion 122 and/or the slide 126 may then be moved to their closed positions, thereby closing the cavity 86 and preparing for the pressing operation.

In fig. 9, the direction of movement of the lower mold portion 120 and the lower vertical slide 124 is also indicated by the double arrow labeled 160. Additionally, the direction of movement of the upper mold portion 122 and the upper vertical slide 126 is indicated by the double arrow designated 162.

Referring to fig. 9 and 10, and additionally to fig. 17 and 18, the interaction of the vertical slides 124, 126 is shown. The vertical slide 126 has an end face 166. The vertical slide 124 has an end face 168. The end faces 166, 168 are each designed as a plane, for example. The end faces 166, 168 may sealingly contact each other such that there is a good seal between the vertical slides 124, 126 in the cavity 86 to form the recess 18.

A comparison of fig. 9 and 10 shows that punches 100, 104 are arranged at a different height level than punches 102, 106. In other words, according to the illustrated exemplary embodiment of fig. 9 and 10, punches 100, 104 are disposed higher than punches 102, 106. For explanation, referring again to the compact 10 shown in fig. 1-4, the compact 10 has a plurality of cutting edges 12a, 12b, 12c, 12d, wherein the cutting edges 12a and 12b are offset with respect to the median plane 20 of the cutting edges and 12c, 12 d. However, as described above, since the cutting edges 34 of the cutting edges 12a, 12b, 12c, 12d are preferably defined by the parting plane of the die 82, the punches 100, 102, 104, 106 are each associated with the vertical position of the cutting edge 12a, 12b, 12c, 12d they will form.

Fig. 7 to 10 already mentioned above show the pressing device 80 in a first state. In the state shown in fig. 7 to 10, the pressing device 80 is completely closed. This means that the mold parts 90, 92, 94, 96, the lower mold portion 120, the upper mold portion 122 and the vertical slides 124, 126 are arranged in their closed position. In addition, the punches 100, 102, 104, 106 are in an end position (pressing position) in which the desired shaping and compaction of the metal powder contained in the cavity 86 can be achieved.

Fig. 11 to 14 and 15 to 18 show the pressing device 80 in different operating states, respectively. The orientation of the views in fig. 11 and 15 corresponds to the orientation in fig. 7. The orientation of the views in fig. 12 and 16 corresponds to the orientation in fig. 8. The orientation of the views in fig. 13 and 17 corresponds to the orientation in fig. 9. The orientation of the views in fig. 14 and 18 corresponds to the orientation in fig. 10.

Fig. 11 to 14 show a state in which the mould parts, i.e. essentially both mould parts, are arranged in their closed position. The die parts are those parts that do not act as punch parts. The mold components include lateral mold components 90, 92, 94, 96, a lower mold portion 120, an upper mold portion 122, and vertical slides 124, 126, if present.

The mold parts define portions of the cavity 86 that do not move during the actual pressing operation. Thus, in particular, the cross-sectional views shown in fig. 13 and 14 show the cavity in a filled position for receiving the non-compacted metal powder, wherein the representation of the metal powder is omitted for illustrative purposes. The orientation of the view in fig. 13 follows the line XIII-XIII in fig. 12. The orientation of the view in fig. 14 follows the line XIV-XIV in fig. 12.

In fig. 12, double arrows denoted by 180, 182, 184, 186 each indicate the pressing direction or pressing axis of the punches 100, 102, 104, 106. Punches 100, 104 are movable parallel to the X axis. The punches 102, 106 are movable parallel to the Y axis. The hard metal powder introduced into the cavity 86 by the filling unit 152 (fig. 9) is compacted in a desired manner by movement of the punches 100, 102, 104, 106.

Referring again to fig. 13 and 14, the design of the cavity 86 will be further explained. An underside 190 (fig. 14) of the cavity 86 is at least partially formed by the lower mold portion 120 and the vertical slide 124 (if present). An upper side 192 (fig. 13) is at least partially defined by the upper mold portion 122 and the vertical slide 126 (if present).

The lower side 190 and the upper side 192 substantially correspond to the lower base surface 30 and the upper base surface 28 for the compact 10.

As described above, the transition 42 is formed on the compact 10 between the base surfaces 28, 30 and the peripheral area 32. The transition 42 is arranged on the (4) side of the peripheral region 32 of the base surfaces 28, 30, respectively, and not on the cutting edge 12. The transition 42 is at least partially provided with a radius and/or a chamfer. In particular, the chamfer, radius with tangential cut and similar profile on the compact 10 are preferably defined in the die 82 by a die component that does not have to have an excessive taper for this purpose.

In this regard, reference is made to the lower projection, indicated at 194, of the mold part 94 in FIG. 13, and to the upper projection, indicated at 196, of the mold part 96 in FIG. 14.

The projections 194, 196 form cross-sections at the edges of the lower side 190 and the upper side 192, respectively, of the cavity 86. Thus, the projections 194, 196 in the compact 10 allow the transition 42 to have a radius, chamfer, tangentially advance, etc.

In this case, it should be noted that preferably no vertically active punches are connected to the lateral die parts 90, 92, 94, 96 provided with corresponding projections 194, 196 to form the transition 42. For example, in the embodiment shown in fig. 13 and 14, if the lower mold portion 120 and/or the upper mold portion 122 are designed as active punches, this would result in an unfavorable pressure distribution or microtexturing during pressing. Those areas of the cavity 86 defined by the projections 194, 196 will be outside the effective range of such vertical punches. This means that only the transition portion 42 of the compact 10 does not have sufficient strength. An unfavorable or unstable microstructure may be caused in the compact 10.

In this case, it should be noted that it is advantageous to arrange the punches 100, 104 and 102, 106 on different vertical planes. The vertical offset between the opposed pairs of punches 100, 104 and 102, 106 allows for uniform compaction of the hard metal powder. In other words, the powder arranged in the cavity 86 in the region of the lower projection 194 of the die parts 90, 94 is compacted by the punches 102, 106. In addition, the powder arranged in the region of the upper projections 196 of the die parts 92, 96 is compacted by the punches 100, 104. Punches 100, 104 and 102, 106 form pressure shaft pairs 180, 184 and 182, 186 that intersect but are spaced apart from each other.

In addition, refer to the state of the pressing device 80 shown in fig. 15 to 18. In fig. 15 to 18, the cavity 86 is opened so that the compact 10 can be removed. For illustrative reasons, the compact 10 is shown in fig. 15-18 in a "suspended state" (Schwebezustand), i.e., in a position and orientation initially defined by the cavity 86 in the closed state.

The perspective view shown in fig. 15 exemplarily shows the cutting edge 12 associated with the (upper) base surface 28 on the compact 10, wherein the cutting edge 12 is at least partially formed by a punch 100 cooperating with the die member 90. In addition, the transition created by the protrusion 196 in the die member 92 between the peripheral region 32 of the compact 10 and the base surface 28 is indicated at 42 in fig. 15, see fig. 18.

The schematic diagram in fig. 16 shows that the upper mold portion 122 arranged in front of the compact 10 does not completely cover the compact 10 from the viewpoint of the observer. The transition 42, which is not formed by the upper mold portion 122, protrudes below the upper mold portion 122.

As can be seen in fig. 7-18, in the exemplary embodiment shown, the cavity 86 is formed entirely by the moving parts, which are the punch part and the die part.

Fig. 17 and 18 show the forming sections 200 of the punches 100, 102, 104, 106, which are respectively associated with the cutting edges 12 of the compacts 10. The forming portion 200 is formed as a protrusion or boss facing the center of the cavity 86 at the respective front ends of the punches 100, 102, 104, 106. The shaped portions 200 each form a groove-like clamping surface 36 of the cutting edge 12. At the transition between the forming portion 200 of the punch 100, 102, 104, 106 and the die component 90, 92, 94, 96 associated therewith, a cutting edge 34 is formed in the resulting compact 10.

The cross-section shown in fig. 17 shows the upper cutting edge 34 associated with the upper base surface 28 of the compact. The cross-section shown in fig. 18 shows the lower cutting edge 34 associated with the lower base surface 30 of the compact 10. The free surfaces 38 (see again fig. 1-4) associated with the respective cutting edges 12 may be defined by a lower mold portion 120 and an upper mold portion 122. The free surface 38 is typically only slightly inclined with respect to the horizontal plane so that a corresponding shape of the lower and upper mould parts 120, 122 can be achieved without excessive wall thickness reduction or without excessively sharp cuts.

The key to making the compact 10 in the compaction apparatus 80 is that no vertical compaction shaft is used. The main pressing axes are lateral and transverse pressing axes 180, 182, 184, 186, see fig. 12. In this way, a particularly symmetrical design of the compact 10 can be produced at least near net shape by hard metal pressing. This allows for a significant reduction in the post-processing requirements.

The concepts according to fig. 6 to 18 allow for a greater degree of design freedom and for a proper design of the compact 10 and the cutting insert 66 based thereon (fig. 5).

Referring to fig. 19, an exemplary embodiment of a method for manufacturing a hard metal compact is shown by means of a schematic block diagram. The green compact produced according to the method can be used for the manufacture of cutting inserts, in particular for the manufacture of indexable inserts of complex geometry. Preferably, the method allows the manufacture of compacts having lower post-processing requirements, in particular having low processing costs.

The method comprises step S10, providing a multipart mould in step S10. Following is a step, labeled S12, in which a cavity in the mold is at least partially formed in step S12. Preferably, the cavity is formed by a plurality of movable mould parts. Specifically, step S12 may include providing a plurality of mold components and possibly a lower mold portion. After step S12, the cavity is not yet fully closed.

Next is step S14 which includes filling the cavity with hard metal powder. In particular, filling may be accomplished by a filling shoe, which may be fed from above to the opening of the cavity. In this way, the hard metal powder enters the cavity by gravity. When the cavity is sufficiently filled, the filling shoe moves away from the opening of the cavity.

Next is step S16 which includes closing the cavity by feeding the upper mold portion. Advantageously, the lateral punch is moved slightly outwards when the cavity is closed by the upper mould part. In this way, filling in the direction of the lateral (horizontal) part of the cavity is supported. Retraction of the lateral punch may create a negative pressure, which results in a suction effect or a post-dispensing effect.

A majority of the cavity is defined by the upper mold portion, the lower mold portion and the lateral mold components. Steps S12 and S16 may also include a feed slide, in particular a vertical slide. Preferably, the slide is coupled to the lower and/or upper mould part. The slide may be used to define a hole or groove in the resulting compact.

Another step S18 includes holding the movable mold part. In particular, the die parts, the lower die part, the upper die part and, if present, the slide can be locked form-and/or force-locked to withstand the pressing pressure and produce the compact with the desired accuracy.

The step labeled S20 describes the actual pressing process. The compaction of the hard metal powder is mainly performed by means of a lateral punch. The lateral punch may be fed laterally onto the cavity to compact the powder. Preferably, the lateral punch is coupled to the lateral die member. This may for example comprise a common guide surface or guide groove. In other words, as an example, at least some of the lateral mould parts may provide guidance for the respective lateral slide. In this way, the mold can be made very compact.

The pressing step S20 is followed by step S22, which step S22 includes opening the cavity. The lateral punch and the movable die part, optionally including a vertically movable tool part (e.g., an upper or lower die part with a slide), move to an open position to enable removal of the compact.

Additional steps, in particular post-treatment steps and/or treatment steps, may be present. In this way, the green compact can be brought into a desired shape. The compact may be fed into a sintering device for manufacturing a cutting tool, in particular a cutting insert or insert, based on the compact by sintering.

Claims (37)

1. A method of manufacturing a near-net-shape hard metal compact, the method comprising the steps of:

-providing a multi-part die (82) comprising a plurality of lateral die parts (90, 92, 94, 96) defining sides of a cavity (86) for the compact (10),

wherein at least one of the lateral mould parts (90, 92, 94, 96) further defines a portion of an upper side (192) of the cavity (86),

-feeding the lateral mould parts (90, 92, 94, 96),

-feeding at least two lateral punch parts (100, 102, 104, 106),

wherein at least two of the lateral die parts (90, 92, 94, 96) are provided with guide grooves (110, 112, 114, 116) for lateral punch parts (100, 102, 104, 106),

-feeding a filling unit (152) through an opening of the cavity (86) and filling the cavity (86) with hard metal powder,

-feeding at least one upper mould part (122), the upper mould part (122) defining a part of an upper side (192) of the cavity (86),

-holding the lateral mould parts (90, 92, 94, 96) and the upper mould part (122),

-compacting the hard metal powder with at least two lateral punch members (100, 102, 104, 106), and

-opening the lateral die parts (90, 92, 94, 96), the upper die part (122) and the lateral punch parts (100, 102, 104, 106) to demould the compact (10),

wherein the lateral punch parts (100, 102, 104, 106) are movable parallel to a first plane and the upper mould part (122) is movable parallel to a second plane, and wherein the first plane is a horizontal plane and the second plane is a vertical plane,

wherein the hard metal powder fills the cavity (86) in a direction parallel to the second plane,

wherein the lateral punch member (100, 102, 104, 106) is a main punch and there is no vertical main punch moving in a direction parallel to the second plane, an

Wherein the upper mold portion (122) releases an opening of the cavity (86) to fill the cavity (86) with the hard metal powder when the upper mold portion (122) is removed from the cavity (86).

2. The method of manufacturing a near-net-shape hard metal compact of claim 1, further comprising:

-providing at least one of the lateral mould parts (90, 92, 94, 96), further defining a portion of an underside (190) of the cavity (86),

-providing at least one lower mould part (120), the lower mould part (120) defining a part of an underside (190) of the cavity (86), and

-holding the lower mould part (120) together with the lateral mould parts (90, 92, 94, 96) and the upper mould part (122).

3. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein the lateral die parts (90, 92, 94, 96), the upper die part (122) and the lower die part (120) are fixed during compaction, and wherein the lateral punch parts (100, 102, 104, 106) are used for compacting the hard metal powder.

4. A method of manufacturing a near net-shape hard metal compact according to claim 3, wherein the compaction process comprises lateral compaction by the lateral punch members (100, 102, 104, 106).

5. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein the lateral die parts (90, 92, 94, 96) are movable parallel to the first plane.

6. A method of manufacturing a near-net-shape hard metal compact according to claim 2, wherein the lower die portion (120) is movable parallel to the second plane.

7. The method of manufacturing a near-net-shape hard metal compact of claim 2, wherein the top mold portion (122) is coupled to an upper vertical slide (126), the upper vertical slide (126) forming a recess (18) in the compact (10), wherein the upper vertical slide (126) is movable parallel to the top mold portion (122).

8. A method of manufacturing a near net shape hard metal compact according to claim 7, wherein the recess (18) passes vertically through the compact (10).

9. The method of manufacturing a near-net-shape hard metal compact according to claim 7 or 8, wherein the lower die portions (120) are coupled to respective lower vertical slides (124).

10. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein the step of feeding the lateral die parts (90, 92, 94, 96) comprises: feeding three or more of said lateral mould parts (90, 92, 94, 96) movable towards and away from each other to open or close said cavity (86).

11. A method of manufacturing a near-net-shape hard metal compact according to claim 10, wherein the lateral die parts (90, 92, 94, 96) together define the horizontal boundaries of the compact (10).

12. A method of manufacturing a near-net-shape hard metal compact according to claim 9, wherein the final shape of the cavity (86) and the compact (10) is defined entirely by the movable lateral die parts (90, 92, 94, 96), the lower die portion (120), the upper die portion (122), the upper vertical slide (126), the lower vertical slide (124) and the lateral punch parts (100, 102, 104, 106).

13. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein each lateral punch part (100, 102, 104, 106) arranged in the guide groove (110, 112, 114, 116) is associated with a respective lateral die part (90, 92, 94, 96), and the direction of movement of the lateral punch parts (100, 102, 104, 106) is parallel to the direction of movement of the lateral die parts (90, 92, 94, 96).

14. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein at least two lateral punch members (100, 102, 104, 106) are vertically offset from each other.

15. A method of manufacturing a near-net shape hard metal compact according to claim 14, wherein the two pairs of lateral punch members (100, 102, 104, 106) are vertically offset from each other.

16. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein the lateral punch members (100, 102, 104, 106) form part of the shape of the compact (10) that is not vertically demoldable.

17. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein the lateral die parts (90, 92, 94, 96) form a transition (42) between a peripheral area (32) of the compact (10) and at least one of an upper base surface (28) or a lower base surface (30) of the compact (10).

18. A method of manufacturing a near net shape hard metal compact according to claim 17, wherein the transition (42) comprises a radius or chamfer.

19. The method of making a near-net-shape hard metal compact of claim 17, wherein at least one of an upper base surface (28) and a lower base surface (30) of the compact (10) is made in the cavity (86) without a punch.

20. A method of manufacturing a near-net-shape hard metal compact according to claim 1 or 2, wherein four lateral die parts (90, 92, 94, 96) are provided in order to form a compact (10) for a rhombus-shaped indexable insert, the lateral die parts (90, 92, 94, 96) at least partially defining four sides of the compact (10) and being connected to four lateral punch parts (100, 102, 104, 106), the four lateral punch parts (100, 102, 104, 106) defining four clamping faces (36) on four outer circumferential sides of the compact (10), wherein the upper die part (122) is for forming an upper base face (28), the lower die part (120) is for forming a lower base face (30), the upper die part (122) is provided for being coupled to an upper vertical slide (126), the lower die part (120) is provided for being coupled to a lower vertical slide (124), wherein the upper vertical slide (126) and the lower vertical slide (124) together form a channel opening (18) in the compact (10).

21. A method of manufacturing a sintered blank for a cutting tool (66) according to the method of any one of claims 1 to 20.

22. A method for manufacturing a hard metal cutting tool, the method comprising:

-manufacturing a compact (10) according to the method of any one of claims 1 to 20,

-treating the part with or without limited post-treatment, and

-sintering the compact (10).

23. A method for making a hard metal cutting tool according to claim 22 wherein said cutting tool is a cutting insert.

24. A method for manufacturing a hard metal cutting tool according to claim 22 or 23, wherein handling a part with limited or no post-treatment is transferring the compact (10) from a pressing device to a sintering device.

25. An apparatus (80) for near-net shape manufacturing of a hard metal compact (10), the apparatus (80) comprising:

-a bed (84),

-a multi-component mould (82) configured to form a cavity (86) for a compact (10), the mould (82) comprising a plurality of lateral mould parts (90, 92, 94, 96), the lateral mould parts (90, 92, 94, 96) defining sides of the cavity (86), wherein at least one of the lateral mould parts (90, 92, 94, 96) further defines a portion of an upper side (192) of the cavity (86),

-an upper mould portion (122) defining a portion of an upper side (192) of the cavity (86),

-a punch unit (98) having at least two lateral punch parts (100, 102, 104, 106), wherein at least two of the lateral die parts (90, 92, 94, 96) are provided with guide grooves (110, 112, 114, 116) for the lateral punch parts (100, 102, 104, 106), and

a filling unit (152) having a filling shoe (154), the filling shoe (154) being feedable to an opening of the cavity (86) for filling the cavity (86) with hard metal powder,

wherein the lateral mould parts (90, 92, 94, 96) and the upper mould part (122) are movable between an open position and a closed position,

wherein the lateral die parts (90, 92, 94, 96) and the upper die part (122) define a surface of the compact (10) in the closed position,

wherein the lateral punch parts (100, 102, 104, 106) are movable along guide grooves (110, 112, 114, 116) in the lateral die parts (90, 92, 94, 96) for compacting the hard metal powder,

wherein the lateral punch parts (100, 102, 104, 106) are movable parallel to a first plane and the upper mould part (122) is movable parallel to a second plane, and wherein the first plane is a horizontal plane and the second plane is a vertical plane,

wherein the hard metal powder fills the cavity (86) in a direction parallel to the second plane,

wherein the lateral punch member (100, 102, 104, 106) is a main punch and there is no vertical main punch moving in a direction parallel to the second plane, an

Wherein the upper mold portion (122) releases an opening of the cavity (86) when the upper mold portion (122) is removed from the cavity (86) to fill the cavity (86) with the hard metal powder.

26. The apparatus for near-net shape manufacturing of hard metal compacts according to claim 25, further comprising a lower die portion (120) defining a portion of an underside (190) of the cavity (86), wherein at least one of the lateral die components (90, 92, 94, 96) further defines a portion of the underside (190) of the cavity (86), wherein the lateral die components (90, 92, 94, 96), the upper die portion (122) and the lower die portion (120) are fixable in the closed position.

27. An apparatus for near-net shape manufacturing of hard metal compacts according to claim 25 or 26, wherein the lateral die parts (90, 92, 94, 96) are movable parallel to a first plane.

28. The apparatus for near-net-shape manufacturing of hard metal compacts according to claim 26, wherein the lower die portion (120) is movable parallel to the second plane.

29. The apparatus for near-net shape manufacturing of hard metal compacts according to claim 26, further comprising a holding unit (150), the holding unit (150) securing the lateral die parts (90, 92, 94, 96), the upper die portion (122) and the lower die portion (120) to each other in the closed position to form a peripheral area (32) of the compact (10).

30. The apparatus for near-net shape manufacturing of hard metal compacts as claimed in claim 26, wherein the upper die portion (122) is coupled to a vertical slide (126), the vertical slide (126) forming a recess (18) in the compact (10), wherein the vertical slide (126) is movable parallel to the upper die portion (122).

31. The apparatus for near-net shape manufacturing of hard metal compacts as claimed in claim 30, wherein the recess (18) passes vertically through the compact (10).

32. An apparatus for near-net-shape manufacturing of hard metal compacts according to claim 30 or 31, wherein the lower die portion (120) is connected to a respective vertical slide (124).

33. An apparatus for near-net-shape manufacturing of hard metal compacts according to claim 25 or 26, wherein the compaction of the hard metal powder is performed solely by the lateral punch members (100, 102, 104, 106).

34. The apparatus for near-net shape manufacturing of hard metal compacts as claimed in claim 25 or 26, wherein the lateral die members (90, 92, 94, 96) form a transition (42) between a peripheral area (32) of the compact (10) and at least one of an upper base surface (28) or a lower base surface (30) of the compact (10), wherein the transition (42) comprises a radius or chamfer.

35. An apparatus for manufacturing a sintered blank for a cutting tool (66), the apparatus comprising an apparatus according to any one of claims 25 to 34.

36. A hard metal compact (10) for a rotary tool (66), the compact (10) having:

two base surfaces (28, 30) arranged opposite each other,

a peripheral region (32) extending between the two base surfaces (28, 30), and

a plurality of cutting edges (12) defined by a parting plane of a multipart die (84),

wherein at least one cutting edge (12) is associated with the first base surface (28) and at least one cutting edge (12) is associated with the second base surface (30),

wherein the cutting edge (12) is associated in the peripheral region (32) with a groove-shaped clamping surface (36) which is not perpendicular to the base surfaces (28, 30) and can be demoulded,

wherein the cutting edge (12) and the clamping surface (36) are at least partially defined by a punch member (100, 102, 104, 106), the punch member (100, 102, 104, 106) being fed transversely to the normal of the base surface (28, 30) and realizing a correspondingly oriented micro-structure, the base surface (28, 30) being free of punches and being defined by a lateral die member (90, 92, 94, 96) which can be fed transversely to the normal of the base surface (28, 30) and an upper die portion (122) and a lower die portion (120) which can be fed parallel to the normal of the base surface (28, 30),

wherein the compact (10) is manufactured according to any one of claims 1 to 20.

37. A hard metal compact for a rotary tool according to claim 36, wherein the compact (10) is manufactured by limited or no post-processing.

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